The technology of gas separation is important in many fields, and is particularly important in the field of natural gas processing. Many of the sources of natural gas also contain contaminants that can damage the facilities used to produce and transport the natural gas. Carbon dioxide (CO2) and other acidic contaminants such as hydrogen sulfide (H2S) and carbonyl sulfide (COS) are detrimental components of natural gas. It is preferable to separate these contaminants from the natural gas because their presence reduces the energy content of the natural gas, and they are acidic and corrosive in the presence of water. Excessive amounts of CO2 in the presence of water can result in damage to pipelines and treating systems and must be removed during production.
U.S. Pat. No. 7,316,727 describes a gas separation molecular sieve membrane that may be produced on a porous support. A gas mixture is passed through the porous support and the gas separates into different components across the membrane. The patent describes the membrane and a method of making the membrane. The membrane is made of SAPO-34 crystals (silicoaluminophosphate). The method for making the membrane includes preparing a synthesis gel mixture that is then used to form the SAPO-34 crystals. The synthesis gel mixture comprises an aluminum source, a phosphorous source, a silicon source, one or more organic templating agents and water. The patent describes using an aluminum source comprising aluminum alkoxides, such as aluminum isopropoxide, pseudoboehmite, and crystalline or amorphous aluminophosphates, gibbsite, sodium aluminate, or aluminum trichloride. U.S. Pat. No. 7,316,727 is herein incorporated by reference in its entirety.